NEW CONSERVATION INITIATIVES IN THE 2002 FARM BILL

The role of agri-environmental programs has taken on increased importance in the current Farm Bill debate with an eighty percent increase in Title II funding. However, little empirical evidence exists on the tradeoffs between economic costs and environmental benefits of new agri-environmental programs to assist policymakers in their designs. This paper illustrates some of the budgetary and environmental issues inherent in these initiatives. Several policy options are explored using an environmental simulation model and an economic spatial-equilibrium model for U.S. agriculture. Results indicate abatement levels of nitrogen and pesticides are higher under performance-based policies and those for wind erosion and soil productivity are higher under practice-based policies. Abatement of phosphorus discharge, soil erosion and carbon sequestration remains relatively constant regardless of policy type. A national performance-based conservation policy funded at the $1 billion level has the potential to improve the environmental performance of U.S. farmers by as much as ten percent.Agricultural and Food Policy, Land Economics/Use,

Flexible Conservation Measures on Working Land: What Challenges Lie Ahead?

From 1985 to 2002, most Federal conservation dollars going to farm operators have been to retire land from crop production. Yet most U.S. farmland (850 million acres) remains in active production. The Farm Security and Rural Investment (FSRI) Act of 2002 sharply increased conservation funding and earmarked most of the increase for working-land payment programs (WLPPs). The design and implementation of WLPPs will largely determine the extent to which environmental goals are achieved and whether they are cost effective. We simulate potential environmental gains as well as adjustments in agricultural production, price, and income associated with various WLPP features to illustrate tradeoffs arising from WLPP design and implementation. Competitive bidding with the use of environmental indices to rank producers for enrollment is most cost effective. Payments based on past conservation will help support farm incomes, but limit the amount of additional environmental benefit that can be generated under a fixed budget.Land Economics/Use,

ENVIRONMENTAL COMPLIANCE IN U.S. AGRICULTURAL POLICY: PAST PERFORMANCE AND FUTURE POTENTIAL

Since 1985, U.S. agricultural producers have been required to practice soil conservation on highly erodible cropland and conserve wetlands as a condition of farm program eligibility. This report discusses the general characteristics of compliance incentives, evaluates their effectiveness in reducing erosion in the program's current form, and explores the potential for expanding the compliance approach to address nutrient runoff from crop production. While soil erosion has, in fact, been reduced on land subject to Conservation Compliance, erosion is also down on land not subject to Conservation Compliance, indicating the influence of other factors. Analysis to isolate the influence of Conservation Compliance incentives from other factors suggests that about 25 percent of the decline in soil erosion between 1982 and 1997 can be attributed to Conservation Compliance. This report also finds that compliance incentives have likely deterred conversion of noncropped highly erodible land and wetland to cropland, and that a compliance approach could be used effectively to address nutrient runoff from crop production.conservation compliance, Sodbuster, Swampbuster, conservation policy, agri-environmental policy, nutrient management, buffer practices, Agricultural and Food Policy,

Negative Regulation of Hepatitis C Virus Specific Immunity Is Highly Heterogeneous and Modulated by Pegylated Interferon-Alpha/Ribavirin Therapy

Specific inhibitory mechanisms suppress the T-cell response against the hepatitis C virus (HCV) in chronically infected patients. However, the relative importance of suppression by IL-10, TGF-β and regulatory T-cells and the impact of pegylated interferon-alpha and ribavirin (PegIFN-α/ribavirin) therapy on these inhibitory mechanisms are still unclear. We revealed that coregulation of the HCV-specific T-cell responses in blood of 43 chronic HCV patients showed a highly heterogeneous pattern before, during and after PegIFN-α/ribavirin. Prior to treatment, IL-10 mediated suppression of HCV-specific IFN-γ production in therapy-naive chronic HCV patients was associated with higher HCV-RNA loads, which suggests that protective antiviral immunity is controlled by IL-10. In addition, as a consequence of PegIFN-α/ribavirin therapy, negative regulation of especially HCV-specific IFN-γ production by TGF-β and IL-10 changed dramatically. Our findings emphasize the importance of negative regulation for the dysfunctional HCV-specific immunity, which should be considered in the design of future immunomodulatory therapies

Efficient hydrogen production from the lignocellulosic energy crop Miscanthus by the extreme thermophilic bacteria Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana

<p>Abstract</p> <p>Background</p> <p>The production of hydrogen from biomass by fermentation is one of the routes that can contribute to a future sustainable hydrogen economy. Lignocellulosic biomass is an attractive feedstock because of its abundance, low production costs and high polysaccharide content.</p> <p>Results</p> <p>Batch cultures of <it>Caldicellulosiruptor saccharolyticus </it>and <it>Thermotoga neapolitana </it>produced hydrogen, carbon dioxide and acetic acid as the main products from soluble saccharides in <it>Miscanthus </it>hydrolysate. The presence of fermentation inhibitors, such as furfural and 5-hydroxylmethyl furfural, in this lignocellulosic hydrolysate was avoided by the mild alkaline-pretreatment conditions at a low temperature of 75°C. Both microorganisms simultaneously and completely utilized all pentoses, hexoses and oligomeric saccharides up to a total concentration of 17 g l^-1in pH-controlled batch cultures. <it>T. neapolitana </it>showed a preference for glucose over xylose, which are the main sugars in the hydrolysate. Hydrogen yields of 2.9 to 3.4 mol H₂per mol of hexose, corresponding to 74 to 85% of the theoretical yield, were obtained in these batch fermentations. The yields were higher with cultures of <it>C</it>. <it>saccharolyticus </it>compared to <it>T. neapolitana</it>. In contrast, the rate of substrate consumption and hydrogen production was higher with <it>T. neapolitana</it>. At substrate concentrations exceeding 30 g l^-1, sugar consumption was incomplete, and lower hydrogen yields of 2.0 to 2.4 mol per mol of consumed hexose were obtained.</p> <p>Conclusion</p> <p>Efficient hydrogen production in combination with simultaneous and complete utilization of all saccharides has been obtained during the growth of thermophilic bacteria on hydrolysate of the lignocellulosic feedstock <it>Miscanthus</it>. The use of thermophilic bacteria will therefore significantly contribute to the energy efficiency of a bioprocess for hydrogen production from biomass.</p

Trends in genotypic HIV-1 antiretroviral resistance between 2006 and 2012 in South African patients receiving first- and second-line antiretroviral treatment regimens

The original publication is available at http://www.plosone.org/Publication of this article was funded by the Stellenbosch University Open Access Fund.BibliographyObjectives: South Africa’s national antiretroviral (ARV) treatment program expanded in 2010 to include the nucleoside reverse transcriptase (RT) inhibitors (NRTI) tenofovir (TDF) for adults and abacavir (ABC) for children. We investigated the associated changes in genotypic drug resistance patterns in patients with first-line ARV treatment failure since the introduction of these drugs, and protease inhibitor (PI) resistance patterns in patients who received ritonavir-boosted lopinavir (LPV/r)-containing therapy. Methods: We analysed ARV treatment histories and HIV-1 RT and protease mutations in plasma samples submitted to the Tygerberg Academic Hospital National Health Service Laboratory. Results: Between 2006 and 2012, 1,667 plasma samples from 1,416 ARV-treated patients, including 588 children and infants, were submitted for genotypic resistance testing. Compared with 720 recipients of a d4T or AZT-containing first-line regimen, the 153 recipients of a TDF-containing first-line regimen were more likely to have the RT mutations K65R (46% vs 4.0%; p<0.001), Y115F (10% vs. 0.6%; p<0.001), L74VI (8.5% vs. 1.8%; p<0.001), and K70EGQ (7.8% vs. 0.4%) and recipients of an ABC-containing first-line regimen were more likely to have K65R (17% vs 4.0%; p<0.001), Y115F (30% vs 0.6%; p<0.001), and L74VI (56% vs 1.8%; p<0.001). Among the 490 LPV/r recipients, 55 (11%) had ≥1 LPV-resistance mutations including 45 (9.6%) with intermediate or high-level LPV resistance. Low (20 patients) and intermediate (3 patients) darunavir (DRV) cross resistance was present in 23 (4.6%) patients. Conclusions: Among patients experiencing virological failure on a first-line regimen containing two NRTI plus one NNRTI, the use of TDF in adults and ABC in children was associated with an increase in four major non- thymidine analogue mutations. In a minority of patients, LPV/r-use was associated with intermediate or high-level LPV resistance with predominantly low-level DRV cross-resistance.Stellenbosch University Open Access FundPublishers' Versio

Mucosal-associated invariant T-cell frequency and function in blood and liver of HCV mono- and HCV/HIV co-infected patients with advanced fibrosis

__Background & Aims:__ Mucosal-associated invariant T (MAIT) cells are important innate T cells with antimicrobial and immunoregulatory activity, recently found to be depleted in blood of patients with HIV and HCV mono-infections. In this study, we assessed the impact of HIV, HCV and HCV/HIV co-infection on circulating and intrahepatic MAIT-cells and correlations with liver fibrosis. __Methods:__ In this cross-sectional study, nine healthy subjects, nine HIV, 20 HCV and 22 HCV/HIV co-infected patients were included. Blood and liver fine needle aspirate biopsies were studied using flowcytometry for CD3+CD161+Vα7.2+ MAIT-cell frequency, phenotype and function in HCV mono-infected and HCV/HIV co-infected patients without or with mild fibrosis (Metavir-score F0-F1) or severe fibrosis to cirrhosis (Metavir-score F3-F4). __Results:__ Circulating MAIT-cells were decreased in blood of HCV, HIV and HCV/HIV patients with F0-F1. In HCV/HIV co-infected individuals with severe fibrosis to cirrhosis, the frequency of circulating MAIT-cells was even further depleted, whereas their function was comparable to HCV/HIV co-infected patients with low or absent fibrosis. In contrast, in HCV mono-infected patients, MAIT-cell frequencies were not related to fibrosis severity; however, MAIT-cell function was impaired in mono-infected patients with more fibrosis. More advanced liver fibrosis in HCV or HCV/HIV-infected patients was not reflected by increased accumulation of MAIT-cells in the affected liver. __Conclusions:__ Severe liver fibrosis is associated with dysfunctional MAIT-cells in blood of HCV mono-infected patients, and lower MAIT frequencies in blood of HCV/HIV co-infected patients, without evidence for accumulation in the liver

Frequencies of circulating MAIT cells are diminished in chronic hCV, HIV and HCV/ HIV Co-Infection and do not recover during therapy

Objective Mucosal-associated invariant T (MAIT) cells comprise a subpopulation of T cells that can be activated by bacterial products and cytokines to produce IFN-&gamma;. Since little is known on MAIT cells during HCV infection, we compared their phenotype and function in comparison to HIV and HCV/HIV co-infected patients, and determined the effect of IFN-&alpha;-based and direct-acting antiviral therapy on MAIT cells of HCV patients. Methods Blood samples from patients with chronic HCV (CHCV), virologically suppressed HIV, acute HCV/HIV co-infection (AHCV/HIV) and healthy individuals were examined by flowcytometry for phenotype and function of MAIT and NK cells. Results and Conclusions Compared to healthy individuals, the frequency of CD161+ V&alpha;7.2+ MAIT cells was significantly decreased in patients with CHCV, HIV and AHCV/HIV co-infection. CD38 expression on MAIT cells was increased in AHCV/HIV patients. MAIT cells were responsive to IFN-&alpha; in vitro as evidenced by enhanced frequencies of IFN-&gamma; producing cells. IFN-&alpha;-based therapy for CHCV decreased the frequency of IFN-&gamma;+ MAIT cells, which was still observed 24 weeks after successful therapy. Importantly, even after successful IFN-&alpha;-based as well as IFN-&alpha;free therapy for CHCV, decreased frequencies of MAIT cells persisted. We show that the frequencies of MAIT cells are reduced in blood of patients with CHCV, HIV and in AHCV/ HIV co-infection compared to healthy individuals. Successful therapy for CHCV did not normalize MAIT cell frequencies at 24 weeks follow up. The impact of HIV and HCV infection on the numbers and function of MAIT cells warrant further studies on the impact of viral